In the international telephony marketplace there is historical precedence that varies a number of telephony interface performance parameters across National Boundaries. In the past, products were “nationalized” by either unique hard construction or a combination of hardware and software to adapt to the national deviations. Recent European Union (EU) attempts to “harmonize” these national deviations across the EU have been unsuccessful in achieving complete “harmonization” due to the large base of legacy Telephony Terminal Equipment (TE). Therefore, these national deviations must continue to be accounted for in customer premises equipment.
Yet, manufacturers and telephony operators desire telephony access networks to be capable of adapting to these national deviations without hardware differences in order to reduce terminal equipment compatibility problems, cost and support requirements.
In particular, as it relates to Internet Protocol (IP) based networks, a standards body known as CableLabs was tasked with developing standards for voice-over-IP networks to operate in North America. PacketCable is a communications and signaling standard developed by CableLabs to provide telephony services over a DOCSIS cable modem. DOCSIS stands for Data Over Cable Systems Interface Specifications, which is the CableLabs standard that cable modems use to communicate with the headend and the data network. The ensuing standards developed by Cablelabs/Packetcable provide limited configuration and provisioning capability along with Network Call Signaling (NCS) messages to modify the operation of access devices (called MTAs) based on North American Standards. A Multimedia Terminal Adapter (MTA) is a device that connects to a cable modem and traditional plain old telephone service (POTS) telephone lines to provide telephony service over Hybrid-Fiber-Coax (HFC), and it also interfaces with traditional POTS telephones. These standards essentially describe only one profile of possible operation and are not sufficiently flexible to adapt to all of the variations in the international market.
The present invention is therefore directed to the problem of developing a method and apparatus for enabling Telephony Access Networks to be capable of adapting to national deviations without requiring hardware modifications.